A novel method for synthesis of Co-Al layered double hydroxides and their conversions to mesoporous CoAl2O4 nanostructures for applications in adsorption removal of fluoride ions

摘要

Facile micro-emulsion methods have been developed to synthesize mesoporous Co-Al hydroxide carbonates with rodlike and hexagonal sheetlike morphologies. A series of samples with different molar ratio of cobalt/aluminum were prepared to investigate the impact of cobalt content. Employing transmission electron microscopy, X-ray diffraction analysis and Fourier transformed infrared spectra, the morphology, structure and composition of the products were investigated. Characterized by gas-sorption measurements, the specific surface area of the calcined S-10 sample with the rodlike morphology was as high as 379 m~2/g, which provided this material porosity properties and outstanding fluoride removal efficiency as high as 95.6%. The sorptive removal capacity of fluoride from aqueous solutions by the precursors and their corresponding annealed products was investigated in a batch mode. Also, the adsorption kinetics and isotherms were discussed.